Turbine apparatus



June 18,1946. R. P.-KROON 2,402,418

' TURBINE APPARATUS Filed Jan, 20, 1943 -nt u- 2 WK 25 Her Morn/E 19 IIIFLUID JIZ I Z4 Jill Z! v Fig. 1

WITNESSES:

INVENTOR' W EEm/quT R KeooAf 1- BY whiz ATTORNEY Patented June 18, 1946Application January 20, 1943, Serial No. 412.957

This invention relates to power plants and particularly to thestationary nozzle structure of a gas turbine and it has for an object toprovide an improved device of the character described. It is desirablethat gas turbines start quickly requiring high temperatures to bring theunit up is Claims. (o1. ease-1s) with and supports combustion ofa mu, tnhot to speed with theresult that the turbine issubjected to a rapidincrease in temperature and attendant expansion or the turbine parts. Incontrast to steam turbines, changes in load on gas turbines are normallyaccompanied by changes in temperature of the motive fluid entering theturbine.- Hence, sudden and largetemperature variations.

The blades'on the turbine rotor are, of course,

free to expand longitudinally into the clearance space provided in thecasing. However, if the stationary guide vanes are welded or fixed tothe turbine casing structure, rapid heating of the vanes and thesurrounding parts may cause substantial differential expansion and setup very high stresses which may result in cracking of welds and ruptureof the vanes or ofthe supporting structure.

It is, accordingly, a further object of the invention to provide animproved turbine in which stresses between the stationary guide vanesand compressed air and products of combustion serving to drive theturbine. A power plant of this character is shown in my copendingapplication Serial No. 474,093, filed Januarylifl, 1943, and assigned tothe assignee of the present invention.

The turbine, generally indicated ll, comprises an outer casing structureI I, which, wifli an inner supporting structure, generally indicated l2,provides an annular passage B for the flow of the heated motive fluid.The motive fluid is by nozzle vanes 14 against turbine blades Ii ofaturbine wheel IS. The turbine wheel is carried .on a shaft I! which isjournaled inthe inner sup-' 15 porting structure l2, as by means of ahearing ll.

- The nozzle vanes II are supported in the turbine casing by means ofconcentric rings I! and 2| carrledby the structures H and i2, respee-.tively. These rings are provided with radially aligned holes 22 and 23of a shape eorrupon l to the cross section oi the vanes. 'fiiese holesmay be punched in the rings and serve as mortises .in which the ends ofthe guide vanes are slidably received. The vanes Il may be insertedtheir supporting structure, due to rapid temperature changes, issubstantially eliminated;

These and other objects are effected by the invention as will beapparent irom the following description-and claims taken in connectionwith the accompanying'drawing, forming a part of this application, inwhich: 7

Fig; 1 is a longitudinal sectional view of the stator and rotor .sectionof a turbine in which thepresent invention has been incorporated;

Fig. 2 is an enlarged view of the stator shown in Fig. 1;

Fig. 3 is a view taken substantially on the line IIIIII of Fig. 2 andshown on an enlarged scale;

Fig. 4 is a sectional view taken on the line IVIV of 1; and,

Fig. 5 is an elevational view or an outer guide vane ring, as seensubstantially on the line V-V of F18. 4.

The turbine shown in the drawing may be of any type, although thepresent invention is particularly suitable for use in a gas turbinewherein a heated motive fluid, suchas hot compressed air, serves todrive the turbine. For example, air may .be compressed in a compressor,driven by the turbine, and heated in a suitable combustion substantiallyin the rings i9 and 2| and the assemblyplaeed in the turbinewiththerings seated in recesses 24 provided in the structures II and 2. Therings may then be fixed to the structure in any suitable manner as bywelding or peening. The

'80 mortise openings 22 and 23 inihe ruins hold :the vanes at the properangle to direct the hull! against the turbine blades "and substantiallyprevent lateral movement of the vanes. How- ,ever, the vanes are free tomove longitudinally a5 in the openings. Thus, during rapid temperatureapparatus in which the'compressed air is mixed 6 While the invention hasbeen variations, the ends or the vanes may move, as shown by the brokenlines 22 in Figs. 2 and 3, in'to clearance spaces 25 and 2! providedbetween the ends of the vanes and the structures II and I2 and preventstresses from being developed between the vanes andtheir supportingstructure.

A small clearance may be provided at 28 between the nomle vanes and thewalls of the holes on the supporting n es. so that the vanes are able todistort in bending, without setting up end of the guide vanes in'thesupporting rings.

if desired, the vanes may be fixed, as-hy'welding.

at one end to one of the rings llpr 2i, tlmspenmitting expansion andcontractim of the vanes in the openings of the other ringr 1 shown inbut 3 one form, it will be obvious to those skilled in the art that itisnot so limited, but is susceptible of various changes andmodifications without departing from the spirit thereof, and it isdesired, therefore, that only such limitations shall be placed thereuponas are specifically set forth in the appended claims.

What is claimed is:

1. A turbine comprising an outer casing structure, an innersupportingstructure spaced from said casing and defining therewith apassage for the flow of motive fluid, a first ring member secured to theinside of said outer casing structure, a second ring member secured tosaid inner supporting structure and arranged substantially concentricwith respect to said first ring member, said ring members having aplurality of circumferentially-spaced holes therein, and guide vanesextending across said passage for guiding said motive fluid through saidpassage, the end portions of said'vanes being received in said holes insaid first and second ring members and both end portions of said vanesbeing free to move longitudinally in said holes.

2. A turbine nozzle ring comprising a. pair of ring members disposed inspaced, concentric. relation, a plurality of guide vanes carried by saidring members and extending between them, and means connecting the endsof said vanes to the rings, said connecting means fixing said vanes indefinite circumferentially-spaced relation while permitting limitedlongitudinal movement of both ends thereof. Y

3. A supporting structure'for a nozzle vane for turbines or the like inwhich the-parts are subjected to temperature changes, comprising spacedsupporting members fixed relative to each other, said members havingholes therein, and vanes extending between said members with both endsof the vanes slidably received in said holes whereby said vanes andsupporting members may expand or contract due to temperature changestherebetween a passage for the flow of motive fluid, vanes extendingacross said passage for guiding said fluid through said passage, saidmembers having holes therein to slidably receive the end portions ofsaid vanes, said holes being of a shape corresponding to the crosssection of and receiving the ends of said vanes to substantiallypreventdateral motion while permitting longitudinal movement of each endof said vanes in said holes.

6. In a turbine, a casing, a rotor having a row 'of blades, said casingincluding inner and outer annular structures having exterior andinterior cylindrical surfaces, respectively, at the inlet side of saidblades and spaced radially to suit the height of the latter, a row ofnozzle vanes extending radially between said surfaces and each having alength which is slightly less than the radial distance therebetween,means for retaining said vanes in circumferentially-spaced relation andcomprising inner and outer rings having openings conforming to thesection of and receiving the ends of the vanes so that such ends thereofwithout exerting excessive stresses beare capable of sliding in theopenings; said outer ring fitting the interior cylindrical surface ofthe outer annular structure and said inner ring fitting the exteriorcylindrical surface of the inner annular structure, and means forsecuring the rings in place with respect to the annular structure.

'7. A nozzle structure for turbines or the like comprising a pair ofring niembers disposed in spaced concentric relation, and a plurality ofguide vanes carried by said members and extending between them, saidpair of ring memfbers being formed with radially-aligned holes of ashape correspondingto the cross section of the end portions of saidguide vanes, and said guide vane end portions being received in saidholes for limited longitudinal movement of each end portion thereof.

8. A turbine or the like comprising an outer casing structure, an innersupportingstructure spaced from said casing and defining therewith apassage for the flow of fluid, a first ring member secured to the insideof said outer casing structure, a second ring member secured to saidinner supporting structure and arran ed substantially concentric withrespect to said first ring member, said ring members having a pluralityof circumferentially-spaced holes therein, and guide vanes extendingacross said passage for guiding fluid through said passage, the endportions of said vanes being received in said holes in saidfirst andsecond ringmembers and both end portions being slidable longitudinallytherein.

REDIOUT P. KROON.

